Amblyomma oblongoguttatum Koch 1844

Barbieri, Fabio S., Brito, Luciana G., Barros-Battesti, Darci M., Famadas, Kátia M., Labruna, Marcelo B. & Camargo, Luis Marcelo A., 2012, Redescription of the larva of Amblyomma oblongoguttatum Koch, 1844 (Acari: Ixodidae) by light and scanning electron microscopy, Zootaxa 3579, pp. 80-88 : 81-85

Amblyomma oblongoguttatum Koch 1844 , LARVA

( Fig. 1–10 )

IDIOSOMA: Dorsal surface (fig. 4). Length from apices of scapulae to posterior margin of body 0.631 ± 0.020 (0.592–0.662); greatest width 0.618 ± 0.017 (0.588–0.649); outline oval, with 11 festoons. Setae: 2 central dorsal pairs (Cd1, Cd2), 8 marginal dorsal pairs (Md1–Md8), with Md1 and Md2 before a large wax gland, present in the segment VIII (WdVIII1), and Md3 pair located on the inner side behind of these glands; Md4 – Md8 pairs posterior to large wax gland, each one on a different festoon. Scutum ( Fig. 4 , 8 ): outline subtriangular; length 0.247 ± 0.010 (0.230–0.262) along median line; width 0.400 ± 0.016 (0.377–0.441) at the level of eyes; with few punctuations ( Fig. 8 ). Eyes slightly bulging and shallow; cervical grooves distinct extending parallel to the proximities of setae Sc3, but slightly diverging at the end. Setae: 3 scutal pairs—Sc1, Sc2, Sc3 (fig. 4, 8).

Ventral surface (figs. 4, 9): Anal aperture on central portion of opisthosoma. Setae: 3 sternal pairs (St1, St2, St3), 2 preanal pairs (Pa1, Pa2), 4 premarginal pairs (Pm1–Pm4), 5 marginal ventral pairs (Mv1–Mv5), and 1 pair anal A1.

GNATHOSOMA: Dorsal (figs. 1, 5). Basis capituli triangular in outline; length from posterior margin of trochanter to posterior margin of capituli 0.095 ± 0.005 (0.083–0.103), width 0.178 ± 0.003 (0.171–0.183). Posterior margin straight, cornua absent. Basis capituli on median line with 1 sensillum pair. Palpal grooves segments well-defined (fig. 5, 6). Palpi length from apices of tibiotarsal segment to posterior margin of trochanter 0.140 ± 0.005 (0.133–0.147), width 0.049 ± 0.002 (0.045–0.054); trochanter length 0.021 ± 0.007 (0.016–0.044), width 0.039 ± 0.002 (0.037–0.043); femur length 0.059 ± 0.003 (0.054–0.064), width 0.047 ± 0.003 (0.041–0.051); genu length 0.062 ± 0.003 (0.056–0.069), width 0.041 ± 0.002 (0.035–0.044). Femur with sensillum near seta Fa1 ( Fig. 1 ).

Ventral ( Figs. 1 , 6 ): Basis capituli as illustrated. Hypostome – compact, spatulate, length from apices to post hypostomal seta 0.117 ± 0.004 (0.111–0.124), dental formula 2/ 2 in file teeth, apical corona usually with 9 denticles (fig. 7); 1 pair of hypostomal setae ( Ph 1).

Palpal setae ( Figs. 1 , 5, 6 ): 10 setae on tibiotarsus, 6 terminal (Ttt1 – Ttt6), 2 paraxial (Ttp1, Ttp2) and 2 antiaxial (Tta1, Tta2) (fig. 7); 6 genual setae, 1 paraxial (Gp1), 1 antiaxial (Ga1), 3 dorsal (Gd1, Gd2, Gd3), and 1 ventral (Gv1); 6 femoral setae, 1 paraxial (Fp1), 2 antiaxial (Fa1, Fa2), 1 dorsal (Fd1), and 2 ventral (Fv1, Fv2); trochanter 0. LEGS: Coxa I with 2 triangular short spurs, the external slightly larger; coxa II and III each with 1 short triangular spur ( Fig. 9 ). Setae: 3 on coxa I, 1 anterior (CIa), 1 posterior (CIp) and 1 paraxial (CIpa); coxa II and III, each with 2 setae, 1 anterior (CIIa, CIIIa) and 1 posterior (CIIp, CIIIp). Trochanter lacking spur. Tarsus I length 0.200 ± 0.007 (0.184–0.207), width 0.075 ± 0.004 (0.067 – 0.082). Setae (figs. 2, 3, 10): Dorsal, 2 in dorsal I group ( dI 1, dI 2); 5 dorsal II (dII1 – dII5); 2 dorsal III (dIII1, dIII2); 2 dorsal IV (dIV1, dIV2); 0 dorsal V; 2 dorsal VI (dVI1, dVI2); Ventral, 2 ventral I (vI1, vI2), 2 in II group (vII1, vII2) and 2 in III (vIII1, vIII2); Lateral anterior, 1 in lateral anterior I group (laI1), and 3 in laII group (laII1, laII2, laII3); Lateral posterior, 1 in lateral posterior I group (lpI1) and 3 in lpII group (lpII1, lpII2, lpII3). Ambulacrum as illustrated ( Fig. 2 , 3 , 10 ).

Porotaxy: Dorsal ( Fig. 4 ): Large wax gland—1 pair located on the lateral margin of the idiosoma, on segment VIII, WdVIII1 (30/30 = 30 idiosomal sides containing the pore/ 30 observed idiosomal sides). Lyrifissures – 11 pairs: 1 pair on segment III, LdIII5 (30/30); 1 in IV, LdIV2 (29/30); 2 in V, LdV1 (23/30) and LdV6 (30/30); 1 in VI, LdVI1 (26/30); 2 in VIII, LdVIII4 (25/30) and LdVIII6 (25/30); 2 in IX, LdIX4 (29/30) and LdIX6 (30/30); 2 in XII, LdXII4 (27/30) and LdXII7 (30/30). Small glands – 28 pairs, 3 in scutum, 2 in segment III, SdIII3 (21/30) and SdIII5 (30/30); 1 in IV, SdIV6 (29/30); and one additional asymmetric small gland on the posterior central margin of the scutum, SdV7 (15/15). In alloscutum, 25 pairs on segments: 1 in IV, SdIV2 (27/30); 3 in V, SdV2 (20/30), SdV4 (29/ 30), SdV6 (26/30); 4 in VI, SdVI1 (23/30), SdVI2 (10/30), SdVI4 (29/30), SdVI6 (27/30); 3 in VIII, SdVIII4 (29/30), SdVIII6 (29/30), SdVIII7 (27/30); 3 in IX, SdIX1 (21/30), SdIX2 (29/30), SdIX7 (30/30); 3 in X, SdX1 (13/30), SdX3 (29/30), SdX5 (11/30), and dorsal fovea (dorsal series 7–30/30); 2 in XI, SdXI3 (28/30), SdXI7 (30/30); 2 in XII, SdXII1 (29/30), SdXII7 (29/30); 3 in XIII, SdXIII1 (30/30), SdXIII3 (28/30), SdXIII5 (27/30); 1 in XIV, SdXIV1 (27/ 30).

Ventral ( Fig. 4 ): Large wax glands—4 pairs, one behind each coxa in segments III, IV and V, WvIII1 (30/30), WvIV4 (30/30), WvV5 (30/30); 1 pair located on the 5th. festoon, segment XIII, WvXIII1 (30/30). Lyrifissures—13 pairs on segments: 1 in IV, LvIV6 (28/30); 1 in V, LvV6 (30/30); 1 in VIII, LvVIII5 (26/30); 4 in IX, LvIX1 (28/30), LvIX3 (30/30), LvIX5 (28/30) and LvIX6 (28/30); 1 in X, LvX2 (30/30); 1 in XI, LvXI2 (30/30); 1 in XII, LvXII3 (30/30); 2 in XIII, LvXIII2 (30/30) and LvXIII6 (30/30); 1 in XIV, LvXIV2 (29/30).

Small gland. 21 pairs on segments: 1 in III, SvIII6 (30/30); 1 in IV, SvIV6, (30/30); 2 in V, SvV1 (30/30), SvV5 (29/30); 1 in VI, SvVI2 (30/30); 1 in VIII, SvVIII1 (30/30); 3 in IX, SvIX2 (29/30), SvIX4 (30/30), SvIX4’ (29/30); 3 in X, SvX1 (30/30), SvX3 (29/30), SvX4 (23/30); 3 in XI, SvXI1 (30/30), SvXI3 (29/30), SvXI4 (16/30); 2 in XII, SvXII2 (30/30), SvXII4 (30/30); 2 in XIII, SvXIII3 (30/30), SvXIII6 (30/30); 2 in XIV, SvXIV1 (29/30), SvXIV4 (13/ 30).

Asymmetric lyrifissures found at low frequency, LvXIII6 (01/30), and small glands, SdX6 (01/30), SdXII3 (01/ 30), SdXII4 (01/30), SdXIII6 (02/30), and SvVIII4 (01/30).

Figures

FIGURE 1. Amblyomma oblongoguttatum larva. Gnathosoma dorsal (right) and ventral (left) views. Abbreviations: d—dorsal; v—ventral; a—antiaxial; p—paraxial; t—terminal; F—femur; G—genu; Tt—tibiotarsus.

FIGURE 2. Amblyomma oblongoguttatum larva. Tarsus I dorsal views. Abbreviations: d—dorsal; a— antiaxial; p—paraxial; la—lateral anterior; lp—lateral posterior.

FIGURE 3. Amblyomma oblongoguttatum larva. Tarsus I ventral views. Abbreviations: v—ventral; a— antiaxial; p—paraxial; la—lateral anterior; lp—lateral posterior.

FIGURE 4. Amblyomma oblongoguttatum larva. Segmentation model of the idiosoma. Segments are indicated by Roman numbers (III – VI e VIII – XIV) and delimitated by dashed lines (----); series are indicated by Arabic numbers and delimitated by dotted lines (........). Integumentary structures are illustrated.

FIGURE 5 – 10. Amblyomma oblongoguttatum larva. 5. Gnathosoma, dorsal view (30 µm); 6 Gnathosoma, ventral view (30 µm); 7. Detail of tibiotarsus and hypostome (30 µm); 8. Detail of scutum (30 µm); 9. Coxae I – III (20 µm); 10. Tarsus I, dorsal view (30 µm).